The inventive concept relates generally to semiconductor memory devices. More particularly, the inventive concept relates to nonvolatile memory devices, methods of programming the same, and memory systems comprising the same.
Semiconductor memory devices can be roughly classified into two types based on their ability to maintain stored information when disconnected from power. These types include nonvolatile semiconductor devices, which are generally capable of maintaining stored information when disconnected from power, and volatile semiconductor memory devices, which generally lose stored information when disconnected from power.
Examples of nonvolatile memory devices include read only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically-erasable PROM (EEPROM), flash memory (a type of EEPROM), phase-changeable random access memory (PRAM), magnetoresistive random access memory (MRAM), and ferroelectric random access memory (FRAM). Flash memory can be roughly classified into two types based on the configuration of memory cells and related access circuitry. These types are NOR-type flash memories and NAND-type flash memory.
Examples of volatile memory devices include static random access memories (SRAM), dynamic random access memories (DRAM), and synchronous dynamic random access memories (SDRAM).